10 surprising facts about Komodo dragons

These huge beasts have inspired myths of fantastic proportions. Get to know the real life dragons of Komodo Island.

Komodo dragons were the stuff of legend until explorers in the early 1900s confirmed that these huge beasts are real.
(Photo: GUDKOV ANDREY/Shutterstock)

1. Komodo dragons are originally from Australia

While famous for being from the Indonesian island of Komodo and surrounding islands, the Komodo dragon started off in the Land Down Under. According to fossil records, Komodo dragons moved out of Australia and made their way to the Indonesian islands, arriving on the island of Flores around 900,000 years ago. LiveScience explains how this worked out:

"In the past, researchers had suggested the Komodo dragon (Varanus komodoensis) developed from a smaller ancestor isolated on the Indonesian islands, evolving its large size as a response to lack of competition from other predators or as a specialist hunter of pygmy elephants known as Stegodon.

However, over the past three years, an international team of scientists unearthed numerous fossils from eastern Australia dated from 300,000 years ago to roughly 4 million years ago that they now know belong to the Komodo dragon.

"When we compared these fossils to the bones of present-day Komodo dragons, they were identical," said researcher Scott Hocknull, a vertebrate paleontologist at the Queensland Museum in Australia. 'Now we can say Australia was also the birthplace of the three-meter (10 foot) Komodo dragon,' Hocknull said."

Palaeontology professor Tim Flannery of Macquarie University in Sydney notes that the Komodo dragon may have disappeared from Australia around 50,000 years ago, a disappearance that coincides with the arrival of humans to the continent. It also has disappeared from all but a few isolated islands, and the species is now considered vulnerable to extinction.

2. Komodo dragons are venomous

It's only recently that Komodo dragons were discovered to be venomous. (Photo: Luca Vaime/Shutterstock)

For a long time, it was believed that a Komodo dragon's bite was so dangerous because of the massive number of bacteria thriving in its mouth. As a scavenger beast, its bite must be filled with the deadly microorganisms of rotting flesh and would infect and kill any victim.

The truth, however, was discovered by Bryan Fry, a venom researcher at the University of Melbourne in Australia, who found that the Komodo dragon is indeed one of the few venomous lizards on the planet. It wasn't until 2009 that the decades-long myth of how Komodo dragons kill was finally slayed, and replaced with the truth, thanks in great part to Fry's research.

According to National Geographic, "The team found that the dragon's venom rapidly decreases blood pressure, expedites blood loss, and sends a victim into shock, rendering it too weak to fight. In the venom, some compounds that reduce blood pressure are as potent as those found in the word's most venomous snake, western Australia's inland Taipan."

Unlike a snake, however, which injects venom into a victim through its sharp fangs, a Komodo dragon's venom seeps into large wounds it makes on an animal it attacks. The animal may escape the grip of the dragon, but it won't escape the venom that will eventually bring it down. By then, the Komodo dragon will be not far behind, tracking down its fleeing victim with its keen sense of smell.

3. Inspiration for 'King Kong'

Only reports of myth and mystery existed until explorers set off to confirm the existence of this fearsome prehistoric beast. (Photo: Ethan Daniels/Shutterstock)

While some myths about Komodo dragons are put to rest, others create even more interesting works of fiction. The Komodo dragon became inspiration for the film "King Kong."

In 1912, a Dutch army man, Lieutenant van Steyn van Hensbroek, visited Komodo Island, shot a dragon dead and sent the skin to naturalist, Peter Ouwens, who wrote the first-ever scientific paper on the massive lizards. Fourteen years later, American W. Douglas Burden set off to the Lesser Sunda Islands of Indonesia to capture a dozen giant lizards for the American Museum of Natural History. His memoir of the expedition Dragon Lizards of Komodo, gave the dragons their nickname and its tales of adventures and confrontations with the ‘hoary beast’ inspired the movie King Kong.

The movie's female lead role is said to be inspired by Burden's wife, who went along during his expedition to Indonesia. Meanwhile, the plot line of the great ape being carried back to New York is inspired by Burden bringing back two live Komodo dragons for the Bronx Zoo. Even the 'K' of King Kong is said to be inspired by the hard 'K' of Komodo.

4. Komodo dragons can take down enormous prey

Komodo dragons themselves are massive animals. Measuring as much as 8.5 feet long and weighing as much as 200 pounds, it's no surprise then that they can take down animals as large as wild boar, deer and water buffalo.

To catch their prey, they use an ambush strategy. Matching well with the dirt surroundings of their island home, they lie in wait for an unsuspecting animal to pass by. They then sprint into action, landing a venomous bite before the victim can escape.

While filming for BBC's Planet Earth II, cameraman Mark MacEwan got a chance to see the predators in action. In an interview with Motherboard, he notes, "Komodo dragons are ambush predators, and it's easy to get lulled into a false sense of security," continued MacEwen. "And then suddenly, one of them moves explosively. Huge claws, armor-plated skin — I mean, it's pretty much the ultimate predator. It's an absolutely amazing creature."

8. Komodo dragons can eat 80% of their weight in one sitting

Komodo dragons can eat so much at one sitting that they may go as long as a month before needing another meal. (Photo: Sergey Uryadnikov/Shutterstock)

Not only are Komodo dragons big in size, but they have an appetite to match. When the massive lizards sit down to a meal, they are capable of swallowing down as much as 80 percent of their own body weight in food.

The huge feast and slow digestion mean that after eating, Komodo dragons will go lounge in the sun, with the heat helping to keep their digestion process working away. After the meal is digested, a Komodo dragon will regurgitate what is known as a gastric pellet. Similar to owl pellets, the gastric pellet contains horns, hair, teeth and other bits of prey that can't be digested.

Because their metabolism is fairly slow and they can pound down so much in a single sitting, Komodo dragons can survive on as little as one meal a month.

5. Komodo dragons are infamous for grave robbing

Komodo dragons don't always — or even often — hunt for their meals. Instead, they eat a lot of carrion. They can detect a carcass as far as six miles away.

Unfortunately for humans living among the dragons, that can mean that they feast on the recently buried. This has caused people living on Komodo to switch from graves on sandy ground to clay ground, and add a pile of rocks on top of the grave for good measure.

6. Female Komodo dragons can reproduce without sex

Komodo dragons lay clutches of eggs that hatch in April, when there are a large number of insects for the small hatchlings to feast on. (Photo: Ethan Daniels/Shutterstock)

These ancient beasts remind us not only of the prehistoric dinosaurs featured in the classic movie "Jurassic Park," but their reproductive behavior harkens back to something highlighted in the film as well.

In 2006, a group of researchers verified that female Komodo dragons can reproduce asexually through a process called parthenogenesis. When no males are present, females can still lay a viable clutch of eggs.

When the discovery about Komodo dragon reproduction was made, LiveScience reported:

Parthenogenesis, in which an unfertilized egg develops to maturity, has been found in 70 species of vertebrates, including captive snakes and a monitor lizard species. In most of these reptile cases, this process is their only method of reproduction. In some whiptail lizards, males have become somewhat of an accessory, and all individuals are female. The type of asexual reproduction in whiptail lizards generates all-female offspring.The Komodo dragon, turns out, can do both: they can reproduce sexually or asexually depending on their environmental conditions. At most zoos, females live alone and are kept separate from other dragons.

It was females at two zoos, kept in such solo conditions, that provided the eggs for the researchers to analyze and confirm that Komodo dragons are capable of parthenogenesis — one from London's Chester Zoo and one from the London Zoo. Genetic analysis of some of the eggs from their clutches confirmed that no male contributed to fertilization; the females were both the mother and the father of their offspring.

While parthenogenesis occurs in some 70 species around the world, this was the first time it had been confirmed in Komodo dragons.

7. Komodo dragons are known to cannibalize baby dragons

It may be amazing that female Komodo dragons can make sure the species continues with or without the presence of males. But something that isn't quite so inspiring is that those little offspring might just be an easy meal for an adult dragon.

If other prey isn't available, or it just looks like a youngster would make a nice snack, an adult Komodo dragon is not above snagging one as lunch. For this reason, young Komodo dragons will spend time up in trees, avoiding getting in the path of larger lizards. That's not the only behavior that helps keep them alive to adulthood.

According to the Smithsonian National Zoo, "Because large Komodos cannibalize young ones, the young often roll in fecal material, thereby assuming a scent that the large dragons are programmed to avoid. Young dragons also undergo rituals of appeasement, with the smaller lizards pacing around a feeding circle in a stately ritualized walk. Their tail is stuck straight out and they throw their body from side to side with exaggerated convulsions."

9. You might not be able to outrun a speedy Komodo dragon

Watching a Komodo dragon coming your way might be one of the world's most unnerving scenes. (Photo: Kiwisoul/Shutterstock)

They may look large and lumbering, but these lizards are all muscle and can move with explosive speed. In an all-out sprint, a Komodo dragon can run at an impressive 12 miles per hour. The average human sprints at just 15 miles per hour. So if you are caught by surprise by a charging Komodo dragon that was lying in wait for a meal, you'd better run like your life depends on it. Komodo dragons have been responsible for the death of four people in the last 41 years. Don't underestimate their speed just from the look of their bulk.

10. Komodo dragons are surprisingly playful

So we've talked a lot about the ferocity, speed, grave-robbing and cannibalistic tendencies of these behemoth lizards, but we wouldn't want to leave you with that as the only impression you have of Komodo dragons. There's a softer side to them — sort of.

It turns out Komodo dragons also engage in play. Captive individuals have been observed playing with shovels, shoes and even frisbees. The way the individuals interacted with the objects were shown to be without aggression or food motivation, and would easily be considered play if the dragon were a dog or cat.

Kraken, a dragon kept at Smithsonian National Zoological Park, showed playful behavior with her keepers. Science Blogs writes, "Kraken would tug at or sever shoe laces (with her teeth), and would gently pull objects out of people’s pockets. The keepers then began to introduce boxes, blankets, shoes and Frisbees into Kraken’s enclosure, and many of Kraken’s reactions would be interpreted as playful if witnessed in a mammal. Kraken has also been recorded to play tug-of-war with her keepers. In a detailed, thorough study of Kraken’s interactions with objects and her keepers, Burghardt et al. (2002) concluded that play-like behaviour in Komodo dragons definitely meets the formal criteria for play."

And just in case you wondered what it looks like to play tug-o-war with a Komodo dragon, here's this little bit of cuteness for you (no really, it's cute!):